查尔酮合酶基因重复-歧化的遗传学效应

基因的重复-歧化是生物进化的重要机制。查尔酮合酶（CHS）是类黄酮途径的第一个关键酶,影响植物的多种性状。本文综述了CHS基因经重复-歧化后的假基因化、亚功能化、新功能化、基因互作这4种遗传学效应的表现和发生原因,并从系统发生的角度综述了亚功能化和新功能化的成员在分子进化树上的聚类式样。     

An invertebrate harmfulness scale for research on plant pest diversity and impacts

Traditional methods of quantifying the harmful effects of invertebrates on plants require time-consuming identification of large numbers of individuals at species level. Collected specimens usually are killed; this may be unacceptable for some strictly protected species and may bias the results of subsequent surveys at the same site.

We developed a “harmfulness scale” for quick, non-invasive assessment of invertebrate impacts on plants, and used the scale to test differences in invertebrate attack on species of Balsaminaceae, Polygonaceae and Asteraceae growing in lowland and mountains in Poland. In 2010–2011, we recorded 9190 invertebrates and identified them in situ to family or superfamily level. Among them were 7593 pests, accounting for 82.6% of all recorded organisms. Pests were three times more numerous in the mountains than in the lowland. Balsaminaceae were most heavily attacked by pests (92.9% of all organisms detected on them). Aphidoideae were the most numerous pests.

This method can help reduce the costs and labour required for this type of research, facilitating progress in theoretical biology and in the development of practical phytosanitary measures.     

光谱分析Q型烟粉虱化学感受蛋白CSP1与β-紫罗兰酮的相互作用

为明确烟粉虱在入侵过程中的寄主选择性与其化学感受系统对寄主植物挥发物的分子识别之间的相互作用和化学机理,通过荧光、紫外光谱和圆二色谱等技术分析了烟粉虱化学感受蛋白Bt CSP1与一种重要的植物挥发物成分—β-紫罗兰酮之间的相互作用。结果表明,β-紫罗兰酮与Bt CSP1在不同温度时的猝灭机理不同,300 K(27℃)时二者的亲和力较弱,表观结合常数KA为2.44×105L/mol,较低温290 K(17℃)和高温310 K(37℃)时的3.22×105L/mol和3.23×105L/mol均要低,表明Bt CSP1与β-紫罗兰酮在不同的温度下呈现不同的结合机理,低温时为静态猝灭,而高温时为动态猝灭。通过热力学参数和非辐射能量转移理论分析,β-紫罗兰酮与Bt CSP1蛋白结合时发生了荧光共振能量转移,结合距离为5.2 nm。圆二色谱结果显示,随着β-紫罗兰酮浓度的升高,Bt CSP1蛋白中α-螺旋比例逐渐减少,由纯蛋白时的63%下降到55.9%,二级结构发生了变化。     

基于流固耦合的隔舌位置对双流道泵综合性能的影响

为了研究隔舌位置对双流道泵水力性能与结构性能的影响,针对3种不同隔舌安放角的双流道泵进行双向流固耦合计算,结果表明:水力性能方面,隔舌位置对扬程的影响较小,而对效率的影响较大,3种方案的最大扬程差仅为0.09 m,而最大效率差达1.1%;隔舌位置主要影响隔舌圆角及往第1断面方向附近与叶轮间隙处的压力脉动程度,隔舌安放角越大,压力脉动越强;叶轮旋转1周,蜗壳所受径向力呈现周期性变化规律,叶片扫过隔舌圆角时,蜗壳所受径向力最小,转过90°时径向力达到最大值.增大隔舌安放角可显著减小蜗壳所受径向力.结构性能方面,叶轮应力集中出现在出口吸力面,蜗壳应力集中出现在隔舌圆角附近靠后盖板处,增大隔舌安放角会增加蜗壳的最大应力值,但振幅减小;双流道泵发生10^-5m量级的位移,最大位移出现在蜗壳出口处,主要受叶片通过频率的影响,呈周期变化趋势,且随着隔舌安放角的增大,蜗壳最大变形量增大,振幅减小;隔舌位置对泵的振动速度影响比较明显,增大隔舌安放角,有助于减小振动.     

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为了对寄主植物介导的间接病虫互作机理研究奠定基础,采用光度分析法研究白粉菌侵染中国月季植株对植物体内糖类和蛋白质含量的影响.结果表明:中国月季(Rosa chinensis)感染白粉菌(Sphaerotheca pannosa)后,随着感病时间的延长,蛋白质含量逐渐下降,而总糖含量则呈先升高后降低的趋势;白粉菌侵染对中国月季叶片蛋白质和总糖含量的影响均存在明显的时间效应,随着感病程度增加,蛋白质和总糖的含量均明显降低,蛋白质含量从73.52 mg/g降低至59.92 mg/g,总糖含量从17.84 mg/g降低至8.94 mg/g.     

Functional traits associated with nitrogen use efficiency in wheat

The association between functional traits and nitrogen use efficiency (NUE) was investigated to assist the breeding of nitrogen (N) use-efficient bread wheat (Triticum aestivum ssp. aestivum) varieties. This study combined results from a climate chamber experiment involving 41 spring wheat varieties and a field experiment involving six winter and six spring wheat varieties grown with and without the application of mineral N fertiliser. The climate chamber experiment was analysed by partial least squares (PLS) regression, with several predictors and NUE as response, to identify traits related to NUE. Specific hypotheses were then tested in the field experiment. The PLS indicated six traits of particular importance for overall NUE: leaf chlorophyll (SPAD value) of the top leaf at stem elongation, grains ear^?1, ears pot^?1, straw biomass pot^?1, days between emergence and anthesis, and days between emergence and completed senescence. In the field experiment, the SPAD value of flag leaves of winter wheat around anthesis was positively correlated with NUE and total grain N, at both N levels. Fast development was positively correlated with high NUE and N uptake efficiency in spring wheat. Early senescence of the flag leaf was positively correlated with grain N concentration and negatively correlated with grain-specific N efficiency in winter wheat at low N fertilisation levels. The results indicate that high SPAD value of the top leaf might be a candidate trait that could be used in wheat breeding for improved NUE, while genetic variation in senescence could possibly be used to tailor varieties for different end-use quality when grown at low N. More studies are needed to validate these findings in other environments and for other genotypes.     

Co-application of molybdenum and selenium fertilizers increase uptake,recovery and harvest index of molybdenum and selenium in pepper crop

A pot trial was conducted to clarify the interactions of molybdenum (Mo) and selenium (Se) fertilizers on uptake, harvest index and recovery of Mo and Se by pepper crop (Capsicum frutescens L.). Mo was applied at three rates (0, 0.15 and 0.3 mg kg^?1) and Se at three rates (0, 0.4 and 0.8 mg kg^?1) in soil. Appropriate application of Mo increased Se concentrations in pepper fruit, stem, leaf and root especially in the presence of Se fertilizer. Appropriate application of Se increased Mo concentrations in pepper fruit, stem, leaf and root particularly in the presence of Mo fertilizer. Both Mo and Se had beneficial effects on harvest index and recovery of Mo and Se. These results indicated that there is significant synergetic effect on Mo and Se absorption and translocation, and co-application of these two elements is necessary to produce Mo and Se-rich pepper.     

Nitrogen and vermicompost interaction on soil and leaf nutrient status of kinnow mandarin in vertisols of Jhalawar district

A field experiment entitled “nitrogen and vermicompost interaction on soil and leaf nutrient status of kinnow mandarin in vertisols of Jhalawar district” was conducted at the Fruit Research Farm, Department of Fruit Science, College of Horticulture and Forestry, Jhalawar (Rajasthan) during 2012–13 to study the effect of different levels of nitrogen and vermicompost on physico-chemical properties of soil and leaf micro and macro nutrient contents of Kinnow mandarin. The result indicated that application of T₁₅ treatment i.e. nitrogen at 350 g/plant + vermicompost 20 kg/plant was found best with regard to improvement in soil physico-chemical properties like organic carbon content (0.44%), available nitrogen (N) (379.36 kgha^?1), available phosphorus (P) (25.56 kgha^?1), available potassium (393.29 kgha^?1) and reduces electrical conductivity (0.34 dSm^?1), soil pH (7.42) and calcium carbonate (CaCO₃) content percentage (15.20) of soil.     

柱失效方程中荷载相关特性对承载力抗震设计可靠度的影响

以竖向荷载和水平地震作用组合下的钢筋混凝土柱和钢柱为对象,研究了失效方程中荷载相关特性对柱承载力抗震可靠性的影响。根据现行《混凝土结构设计规范》和《钢结构设计规范》分析了不同柱弯矩轴力相关曲线的特性。结合多个框架结构实例,对比了柱失效方程中荷载相关曲线与规范考虑情形的异同。实例分析表明:水平地震和竖向荷载组合作用下,小偏压RC柱和工字型钢柱的荷载相关曲线与规范考虑的情形较为符合,均近似为负相关的直线;水平地震和竖向荷载组合作用下,大偏压RC柱的荷载相关曲线则与规范考虑的情形有较大出入,存在明显的正相关段部分。在此基础上,考虑失效方程复杂特性,依据已有的荷载和抗力变量概率模型,采用Monte Carlo法分析了水平地震和竖向荷载组合作用下柱的可靠性。结果表明:钢柱和小偏压RC柱的承载力抗震可靠度随轴压力荷载效应比值的变化幅度较小,与规范模式计算结果较接近;大偏压RC柱的承载力抗震可靠度随轴压力荷载效应比值的变化会有较大幅度波动,与规范模式计算结果差异较大;当轴压力荷载效应比值为负时,大偏压RC柱的承载力抗震可靠度会低于规范计算值较多,现行柱可靠性设计方法会偏于不安全。